Apparatus for producing nonwoven scrim fabrics

ABSTRACT

The invention relates to a device for making nonwoven scrim, which device comprises a rotary member distributing two weft threads drawn from two fixedly mounted bobbins. It permits the production of nonwoven scrim of various constructions.

Unite States Patent Seguin 1 Min. 2, W?

[54] APPARATUS FOR PRODUCING [56] References Cited NONWOVEN SCRIM FABRICS UNITED STATES PATENTS [72] Inventor: Pierre Seguin, Chavanoz, France 3,390,439 7/1968 Kalwaites ..28/l CL [73] Assignee: Moulinage et Retorderie de Chavalnoz, 3 4225 1 9 9 Seguin "023/1 CL Chavanoz, (18m), France 3,505,712 4/1970 Seruage ..28/l CL [22] Filed: Oct. 30, 1970 Primary Examiner-Louis K. Rimrodt [211 APPL 85,368 AttorneyNorman c. Armitage, H. William Petty and Luke J.

Wilburn, Jr.

[30] Foreign Application Priority Data Nov. 7, 1969 France ..6938635 [57] SI m The invention relates to a device for making nonwoven scrim, [52] US. Cl. ..28/1 CL, 156/181, l56/43Q, which device comprises a rotary member distributing two weft l56/441 threads drawn from two fixedly mounted bobbins. It permits [5 l Int. Cl ..D02g 3/00, D04h 3/08 th r d tion f nonwoven scrim of various constructions. [58] ..28/l,21;l56/l8l,430,44l

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sum 3 OF 3 INVENTOR. PIERRE SEGUI N TORNEY APPARATUS FOR PRODUCING NONWOVEN SCRIM FABRICS The present invention relates to a device for making nonwoven scrim or net fabrics.

In the present invention, by nonwoven scrim fabrics, we mean fabrics composed of any network constituted on the one hand by longitudinal warp and/or selvage threads and on the other by transverse weft threads, adhered together without interlacing of the warp and weft threads.

U.S. Pat. of Addition No. 79,765 to French Pat. No. 1,208,968 describes a device for producing such scrim fabrics comprising a rotary, hollow swing arm which distributes a weft thread around two selvage threads, this weft thread being brought to the arm through the interior of the axial channel of a shaft which rotates the rotary arm. Such a device has the advantage of great simplicity. However, it is limited in its technical potentialities both in respect to the width of the scrim which may be obtained, and in the speed of production, since only one weftthread at a time can be deposited.

Alternatively, it has been proposed to distribute the weft threads by bobbins disposed around a ringlike support member which is continuously moved by endless chains or belts around spaced selvage and/or warp threads. But such a device has a serious drawback, namely, that there must be moved a substantial mass, due to the weight of the bobbins and their supports, and this mass varies within considerable proportions as the bobbins are emptied.

Likewise there have been attempts to develop, while retaining the principle of the rotary swing arm, a device making it possible to deposit several weft threads about the selvage threads simultaneously. Thus, in French Pat. No. 1,391,900 and corresponding U.S. Pat. No. 3,505,712, it is proposed to deposit two weft threads, one passing through one hollow arm of the rotary member, the other through another arm, these two threads being delivered from bobbins placed on the axis of the rotating support shaft of the swing arm and supported in at least two axially adjacent cages. Unfortunately, such a device requires that these two cages must also be driven in rotation to avoid a torsion and a tangling of the threads. As a result, there is again presented the drawbacks mentioned above, i.e., the necessity for movement of the bobbins carrying the weft threads.

It has now been found, and this forms the subject of the present invention, a device for making textile scrim fabrics comprising a rotary member distributing two weft threads around two selvage and/or warp threads, characterized in that it has two weft thread bobbins fixedly mounted one on the inside and the other on the outside of the space or volume bound by the rotation of the thread-distributing rotary member. In practice, these bobbins are combined with means for guiding the weft threads into the rotary member substantially along its axis of rotation and the bobbins are situated respectively on the inside and on the outside of said space.

The rotary member can be constituted in simple fashion by a disk bearing two hollow guides, or by a hollow tube or cross arm. Advantageously, the rotary member is driven in rotation by a hollow shaft serving as a guide for one of the weft threads, the other thread being directed substantially along the axis of rotation of the rotary member by a centering and guidance element such as an eyelet or the like.

At least one of the bobbins bearing the weft threads may itself be disposed substantially along the axis of rotation of the rotary member.

According to a special form of embodiment, the weft threads are deposited by the rotary element on conical spirals according to French Pat. No. 1,524,991 or U.S. Pat. No. 3,422,51 l, which permits a gradual expansion of the loops of the weft threads as they are formed.

The scrim fabrics formed can be combined continuously with sheets of other warp threads, textile fabrics, papers, metal sheets, various films, and the like.

The scrim fabrics according to the present invention may be made of any filament or natural, mineral, artificial or synthetic thread.

The present invention will be more easily understood with the aid of examples of embodiments and applications of the invention which follow, given by way of indication but in no way limiting, and illustrated by the accompanying drawings in which:

FIG. 1 represents a plan view of the weft sheet-forming portion of a device for producing nonwoven scrim;

FIG. 2 is an end view of the device taken generally along the section AA of FIG. 1 which illustrates the system for feeding the selvage threads and one of the weft threads; and

FIGS. 3, 4 and 5 show various forms of construction of a scrim produced by the device according to the invention.

According to FIG. 1, the weft thread distribution device consists of a rotary member comprising; two bent, tubular arms 1 and 2 radially mounted on a hollow shaft 3 which is rotatably mounted in two bearings 4 and 5 and driven by a transmission belt 6 and pulley 7 connected to a power supply, not shown. Mounted on the shaft 3 forward of the bent arms l and 2 is a main pinion 8 driving a chain 9 which engages the teeth of two other pinions 10 and 11 which drive in rotation spaced thread support members consisting of hollow cones 12, 13 and their respective cylindrical spirals or springs 14, 15. The pinions 10, 11, hollow cones 12, 13 and springs 14l,15 are supported on a cross member 40 which is attached by a sleeve bearing or the like to the rotatable shaft 3 so that the position of cross member 40 may remain fixed during rotation of shaft 3. To prevent rotation of the cross member, cones and springs about the shaft 3 during its rotation, a supporting stop member 41, 42 is positioned below and engages each spring 14, 15, respectively.

As seen in FIG. 2, suitably mounted on a support frame 44 located within the space generated by rotation of the bent arms 1 and 2 and below the main pinion and drive chain is a weft thread bobbin 23 and two selvage thread bobbins 28, 29. The selvage threads drawn from bobbins 28, 29 are kept at sufficient tension by tension devices 30 and 31 and pass axially through the hollow cones l2, l3 and springs 14, 15. Support frame 44 is supportably freely attached by suitable means, not shown, to the support shaft 3 and fixed to the cross member 40.

Positioned in nip relation between the springs 14, 15 are two calender rolls 16 and 17, and two sheets of warp threads 32, 33 are fed respectively from above and below the calender rolls by suitable means, not shown, into the nip portion of the rolls where they are combined with the weft thread sheet, as will be explained.

In operation, a first weft thread 18 drawn from a bobbin 19 passes into the hollow axis of shaft 3, through the bent hollow arm 1 of the rotary member and is wrapped about hollow cones 12, 13 to form a plurality of weft thread sections or reaches extending therebetween. The loop ends of the weft thread reaches slide down and engage the helices of the springs 14 and 15 and the reaches are moved along the springs during their rotation so that the weft thread forms a plurality of spaced, generally parallel weft thread reaches 18a. The selvage threads 20, 21 drawn from bobbins 28 and 29 are kept at sufficient tension, thanks to tension devices 30 and 31 and pass along the axis of rotation of the hollow cones 12, 13 and springs 14, 15, respectively, to be located within the looped ends of the weft thread reaches.

As seen in FIG. 2, a second weft thread 22 drawn from the bobbin 23 traverses a centering guide 24 and bent conduit 25, a tension device 26 and a centering eyelet 27 situated on the axis of the shaft 3 before entering the bent arm 2 of the rotary member. Weft thread 22 is then guided and deposited in reaches 220 about the selvage threads 20 and 21 in the same manner as described with respect to weft thread 18.

As the weft thread reaches 18a, 22a pass along the helices of the springs, they engage and are sandwiched between the incoming warp thread sheets 32, 33 to emerge from the calender rolls 16, 17 in a nonwoven scrim construction consisting of a weft thread layer secured between two warp thread layers and supported by selvage threads 20, 21. The threads of the combined sheets or layers are thereafter bonded to each other at their crossover points by suitable means, such as the application of an adhesive, to product the composite scrim product.

With the foregoing apparatus, various scrim constructions can be provided by varying the pitch and rotational speeds of the respective support springs 14 and 15. By way of example, the device shown in FIG. 1 is provided on one side with a thread support member comprising a simple one spiral spring 14 having a pitch, i.e., the distance between helices, of twice the distance between adjacent weft threads in the final scrim product, while the other spring 15 is provided with a double spiral having a pitch four times the distance between weft threads in the final scrim product. By rotating spring 14 at twice the speed of rotation of the weft thread rotary member or swing arm and spring 15 at the same speed as the rotary member, the weft sheet construction of FIG. 3 is produced.

With the device described, continuous glass weft threads of 680 dtex are fed from supply packages 19 and 23 through guide arms 1 and 2 which are rotated at a speed of 500 r.p.m. Two sheets of warp threads formed of 340 dtex continuous glass filaments having eight warp threads per centimeter are combined with the weft threads (which are arranged at four weft threads per centimeter) to form a scrim width of one meter at a production rate of 5 meters per minute. The threads are adhered in the sheet by application of a plastisized vinyl adhesive and dried in a three meter oven having an interior temperature of 130 C.

Other scrim construction may be produced with the device according to the invention, for example, those having weft thread arrangements 46, 47 and 48, 49 illustrated in FIGS. 4 and 5, respectively. According to FIG. 4, we use two double spirals 50, 52 rotating at a speed equal to the speed of rotation of the rotary member. According to FIG. 5, we use two simple spirals 54, 56 rotating at a speed twice that of the rotary member.

From the foregoing description of the invention it can be understood that the placement of the weft thread supply package support means in the manner disclosed permits continuous placement of a pair of continuous threads about the spaced thread support members of a scrim manufacturing apparatus without the necessity of rotating the thread supply package. By maintaining one of the thread packages positioned within the volume generated by the movement of the path of the second thread as it is guided from its supply package to the thread support members, it is not necessary to move the thread packages to prevent tangling or wrapping of the two threads about each other. The concept of the present invention may be employed with scrim producing machines utilizing thread winding devices other than the type described. For example, stationary support members for the thread packages could be readily employed with a continuous belttype thread such as winding device disclosed in copending US. Pat. application No. 796,l 35 filed Feb. 3, 1969.

That which is claimed is:

1. Apparatus for producing nonwoven scrim fabrics comprising spaced thread support members for receiving a pair of continuous threads wound thereabout to provide a plurality of thread reaches extending therebetween, stationary means for supporting first and second thread supply packages, means for guiding first and second continuous threads from the supported packages and for winding the threads continuously about said spaced thread support members, and said means for supporting the first thread package positioned within the volume generated by movement of the path of the second thread as it is guided from its supply package to said thread support members.

winding means includes first and second thread uide outlet means movable in a closed path about said space thread support members, said first and second thread outlet means being spaced along said closed path of movement for separately guiding the threads, and means for moving said outlet means about said spaced thread support embers to wind the first and second threads thereabout.

4. Apparatus as defined in claim 3 wherein said guiding and winding means further comprises a rotatable support shaft having means for guiding the pair of threads therealong, means attached to and extending radially from said shaft for directing each of the threads outwardly of the shaft in different directions, said radially extending means including said thread guide outlet means displaced radially and along the axis of said shaft from the point of departure of the threads therefrom in the direction of said spaced thread support means, and means for rotating said support shaft to move said outlet means is a closed path about said spaced thread support members.

5. Apparatus as defined in claim 4 wherein said radially extending means comprises 'a' pair of hollow guide arms extending outwardly from said shaft in opposite directions, the outer end portions of said guide arms being bent in the direction of said spaced thread support members and having said thread outlet means at the outer ends thereof.

6. Apparatus as defined in claim 4 wherein said means for guiding the weft threads along the rotatable support shaft includes means for guiding the threads for movement in opposite directions along the shaft, and wherein said means for supporting the first and second thread supply packages are located on opposite sides of the path of movement of said radially extending thread guide means.

7. Apparatus for producing nonwoven scrim "fabrics comprising spaced thread support members for receiving a pair of continuous threads wound thereabout provide a plurality of thread reaches therebetween, a rotatable drive shaft, means mounting said shaft for rotation, a pair of thread guide arms attached to and extending outwardly from said shaft for rotation therewith, outer end portions of each said guide arms containing a thread outlet positioned adjacent said spaced thread support members whereby rotation of said shaft and guide arms moves said outlets in a closed path about said spaced members, means for supporting a first thread package adjacent one end of said shaft and a second thread package adjacent the other end thereof on the opposite sides of the plane of movement of said guide arms, and means for guiding threads from packages on each of said package support means along said shaft to said guide arms.

8. Apparatus as defined in claim 7 wherein one of said thread package support means is positioned within the volume generated by the rotational movement of said thread guide arms, and means attaching said one package support means to said shaft for positional support thereby.

9. Apparatus as defined in claim 8 wherein said means for attaching said one thread package support means to said shaft includes means for supporting additional thread package support means within the volume generated by rotational movement of said guide arms.

10. Apparatus as defined in claim 9 wherein said drive shaft and guide arms are hollow and communicate to guide thread from yarn packages to said thread support members. 

1. Apparatus for producing nonwoven scrim fabrics comprising spaced thread support members for receiving a pair of continuous threads wound thereabout to provide a plurality of thread reaches extending therebetween, stationary means for supporting first and second thread supply packages, means for guiding first and second continuous threads from the supported packages and for winding the threads continuously about said spaced thread support members, and said means for supporting the first thread package positioned within the volume generated by movement of the path of the second thread as it is guided from its supply package to said thread support members.
 2. Apparatus as defined in claim 1 wherein said means for supporting the first thread package also is positioned inside the volume generated by said movement of the path of the first thread to said thread support members.
 3. Apparatus as defined in claim 1 wherein said guiding and winding means includes first and second thread guide outlet means movable in a closed path about said spaced thread support members, said first and second thread outlet means being spaced along said closed path of movement for separately guiding the threads, and means for moving said outlet means about said spaced thread support embers to wind the first and second threads thereabout.
 4. Apparatus as defined in claim 3 wherein said guiding and winding means further comprises a rotatable support shaft having means for guiding the pair of threads therealong, means attached to and extending radially from said shaft for directing each of the threads outwardly of the shaft in different directions, said radially extending means including said thread guide outlet means displaced radially and along the axis of said shaft from the point of departure of the threads therefrom in the direction of said spaced thread support means, and means for rotating said support shaft to move said outlet means is a closed path about said spaced thread support members.
 5. Apparatus as defined in claim 4 wherein said radially extending means comprises a pair of hollow guide arms extending outwardly from said shaft in opposite directions, the outer end portions of said guide arms being bent in the direction of said spaced thread support members and having said thread outlet means at the outer ends thereof.
 6. Apparatus as defined in claim 4 wherein said means for guiding the weft threads along the rotatable support shaft includes means for guiding the threads for movement in opposite directions along the shaft, and wherein said means for supporting the first and second thread supply packages are located on opposite sides of the path of movement of said radially extending thread guide means.
 7. Apparatus for producing nonwoven scrim fabrics comprising spaced thread support members for receiving a pair of continuous threads wound thereabout provide a plurality of thread reaches therebetween, a rotatable drive shaft, means mounting said shaft for rotation, a pair of thread guide arms attached to and extending outwardly from said shaft for rotation therewith, outer end portions of each said guide arms containing a thread outlet positioned adjacent said spaced thread support members whereby rotation of said shaft and guide arms moves said outlets in a closed path about said spaced members, means for supporting a first thread package adjacent one end of said shaft and a second thread package adjacent the other end thereof on the opposite sides of the plane of movement of said guide arms, and means for guiding threads from packages on each of said package support means along said Shaft to said guide arms.
 8. Apparatus as defined in claim 7 wherein one of said thread package support means is positioned within the volume generated by the rotational movement of said thread guide arms, and means attaching said one package support means to said shaft for positional support thereby.
 9. Apparatus as defined in claim 8 wherein said means for attaching said one thread package support means to said shaft includes means for supporting additional thread package support means within the volume generated by rotational movement of said guide arms.
 10. Apparatus as defined in claim 9 wherein said drive shaft and guide arms are hollow and communicate to guide thread from yarn packages to said thread support members. 